Skip to main content
1 of 2
Denis Serre
  • 52.3k
  • 10
  • 146
  • 300

Divisibility of polynomials is a much more rigid property than in integers. Given an integer $n$, another $N$ has a non-zero probability $\frac1n$ to be a multiple of $n$. On the contrary, the probability (no rigour here) that a ``random'' polynomial $P\in{\mathbb C}[X]$ be a multiple of a given one $q$ is zero. For instance, $P$ is a multiple of $X$ iff $P(0)=0$, an event of probability $0$.

If you increase the structure, by either considering multi-variate polynomials, or polynomials with coefficients in $\mathbb Z$, you ``simplify'' even more, in the sense that you have additional criteria for divisibility of primality (Newton's polygon, Eisenstein's criterion, ...), and you have a huge theory (Galois' theory) which you can use and abuse.

Denis Serre
  • 52.3k
  • 10
  • 146
  • 300